They probably have a thousand extra genes to pull out when new conditions or substrate presents itself. Maybe it is just the same thing doing what it is supposed to do. Keep your eye on them, collect a sample, maybe you can find someone at a university to sequence the ITS for you! Certainly worth a try!

Martin, neither have I! I pass these on a daily basis and usually they are white, dry and crusty, with what I typically associate Schizophyllum commune. We’ve had a lot of rain lately, and they seem to have taken on some rather interesting new colorations and growth patterns. I found a few other examples of this online, but it’s new to me. I have heard they can grow in humans and now experience a healthy paranoia whenever photographing. :)